This invention relates to the granulation of materials and more particularly to the granulation of materials using elongated rotating cutters.
The granulation of materials using an elongated rotating cutter is illustrated in prior U.S. Pat. No. 3,837,586 which issued Sept. 24, 1974 to Perschbacher et al. It is desirable in such an arrangement to produce granules at the highest possible rate. One way of attempting to increase the rate is to increase the rate at which material is fed to the cutter. This requires a corresponding increase in the number of revolutions of the cutter and of the rollers that are commonly used to feed the material. There is, however, a limitation to the rotational velocity of the cutter because of wear and noise considerations. In addition, certain plastic materials, particularly highly viscous synthetics, permit only limited discharge speeds because of adverse sheer effects that take place within outlets at elevated speeds.
To increase production within the foregoing velocity limitations, it is customary to increase the axial length of the cutter to increase the amount of material that can be supplied and cut simultaneously. This, however, makes each cutter long, heavy and expensive. The apparatus which incorporates the cutter is, in turn, unwieldly, bulky and difficult to control, particularly in the adjustment of the cutting head.
Accordingly, it is an object of the invention to facilitate the granulation of materials, particularly materials in stranded form.
Another object of the invention is to increase the rate at which granules can be produced by a machine with a cutter of prescribed axial length operating at a specified rotational speed.
A further object of the invention is to increase the rate of granulation without the need for changing the speed of the cutter or of increasing its axial length.